The present invention relates to a liquid ejection apparatus and a method for supplying liquid in a liquid ejection apparatus.
Inkjet printers (hereinafter referred to as printers) are widely known as liquid ejecting apparatuses for ejecting liquid onto a target. Such a printer has a reciprocating carriage on which a recording head (liquid ejection head) is mounted. The printer ejects ink (liquid) supplied to the recording head from nozzles, thus performing printing on a recording medium serving as a target.
Among such printers, a printer used for performing a large amount of printing has an ink cartridge (liquid container) of a large capacity on the printer main body. Ink is supplied to a recording head through an ink supply tube by means of pressure generated by a pressure pump. However, in this configuration, if a minute hole is formed in the ink supply tube, pressurized ink leaks to the outside from the ink supply tube. To avoid such possibility of oil leakage, printers such as the one disclosed in Japanese Laid-Open Patent Publication No. 2003-220711 have been proposed.
The printer disclosed in Japanese Laid-Open Patent Publication No. 2003-220711 has an ink supply pump mounted on a reciprocating carriage. The ink supply pump includes a cylindrical member and a movable member. The cylindrical member has an axis extending along the moving direction of the carriage, and the movable member slides in the cylindrical member. An ink inlet is provided at one end of the cylindrical member to introduce ink from an ink cartridge, and an ink outlet is provided at the other end to discharge the ink to the recording head. A one-way valve is provided in the movable member to permit ink to flow only in a direction from the ink inlet toward the ink outlet. When the reciprocating carriage accelerates or decelerates, the movable member moves in the cylindrical member relative to the carriage. Accordingly, ink that is introduced into the cylindrical member from the ink cartridge through the ink inlet passes through the one-way valve, and is then discharged to the recording head through the ink outlet.
However, the cylindrical member, which is moved by inertia relative to the carriage as the carriage reciprocates, increases weight of the entire carriage, thus increases vibration generated when the carriage is moved. The cylindrical member also increases power consumption required for causing the carriage to reciprocate.